The 'Spectrum (Say My Name)' singer joined in a sing-a-long with passengers after a show in London.

Florence Welch was spotted riding the underground in London following a Kendrick Lamar gig in the capital this weekend and joined in with a sing-a-long with passengers on the Tube.

The 'No Light, No Light' singer had entered a packed carriage after the show at the Hammersmith Apollo when she was spotted by fans.

"Florence jumped on the Tube after Kendrick and, as you can imagine, every carriage was packed," a source told The Sun. "At first she tried to keep a low profile but it didn't take long for a few people to recognise her."

They continued: "They started singing 'You've Got The Love' but instead of bailing at the next stop, Florence joined in. It was brilliant."

The Florence & The Machine star then also reportedly breaking out into the rapper's song 'Backseat Freestyle'.

The female star is not the first celebrity to be spotted using the London public transport network in recent times.

Rihanna is often seen riding on the tube during her visits to the capital and famously took the underground to one of her shows on her 'Loud' world tour.